084 PALEONTOLOGY OF ILLINOIS. 



Clathropora, Goscinella, Coscinium, Coscinotrypa, Evactinopora, 

 Reptaria and Semiopora are also included. 



Upon what grounds the last seven genera are placed into the 

 same family with Fenestella, etc., is beyond our comprehension; 

 and we are thoroughly satisfied that no one who has paid even 

 the most cursory attention to fossil Bryozoa, will follow him. 

 Clathropora differs from Ptilodictya only in its mode of growth, 

 and Coscinella and Coscinium are distinguished from Intrapora 

 and Cystodictya in precisely the same manner. In their inter- 

 nal and really essential structure each pair of these genera is 

 practically identical. Co&cinotrypa Hall, is a pure synonym for 

 Coscinium* while Semiopora, as defined and figured by Hall, 

 (Pal. N. Y. Vol. 6, 1887,) is indistinguishable from Phssnopora. 



Evactinopora also, though regarded by us as a very good 

 generic group, is distinguished from Glyptopora and the other 

 genera comprised in our CYSTODICTYONID.E, almost solely by char- 

 acters resulting from its peculiar style of growth. The zooecial 

 features are essentially the same in all, constituting the CYSTO- 

 DICTYONID^E one of the most natural and easily recognized fami- 

 lies of Palaeozoic Bryozoa. We were, therefore, not a little dis- 

 appointment at finding that the family was not adopted by 

 Mr. Miller. In splitting up the family and re-distributing the 

 genera he has been very unfortunate, especially in placing one 

 among the CERAMOPORID.E and several with the FENESTELLHLE. 

 The remainder he puts with the STICTOPORIDJE which is a less 

 unreasonable allocation. 



Rcptaria also, surely has nothing in common with the Fenes- 

 tellidas, and, if it is a bryozoan at all, must go with Hederella 

 into the Cyclostomata near the Tubuliporidse. 



*It should be remarked here that Mr. Miller regards Glyptopora Ulr., (erroneously 

 written Glyptotrypa by him) as not distinct from Coscinium Keyserling, and that he 

 has apparently overlooked the new species of Glyptopora described in this volume. 

 He gives no reasons for thus ignoring our genus, and it is a little surprising to find 

 that he has not emended the definition of Coscinium so as to cover Glyptopora, but 

 leaves it so that its terms include only the cribriform species for which Keyserling 

 proposed the genus and for which the name was adopted by Hall, Ulrich and others. 

 On the other hand he accepts Hall's Coscinotrypafor Coscinium cribri-forme wh ch we, 

 in accordance with the anthor of the species, regard as one of the most typical species 

 of Keyserling's genus. Such a proceeding does not appear just to us. We may add 

 further that the characters which he assigns to Coscinotrypa ought to be joined to his 

 description of 'Coscinium to make it complete. 



